Australia will boost its alliance with the United States and Japan and work more closely with India as power shifts in the Asia-Pacific region.
Although also aiming to accommodate China and improve military relations with Beijing, the new American Defence Secretary, Leon Panetta, told reporters that the US and Australia wanted to "make very clear to those that would threaten us that we're going to stick together".
The two countries are moving closer towards a significant boost to their alliance, including the prepositioning of American hardware in Australia, greater US use of Australian bases and ports, and increased access to Australian training, exercise and test ranges.
Greater focus will also be paid to the South Pacific, including further pressure on Fiji to return to democracy.
The two countries have also agreed to greater military co-operation in space and to treat a cyber attack on one as an attack on both, triggering the mutual defence provisions of the Anzus treaty.
"This represents a new operational dimension for the US alliance," Australian Foreign Minister Kevin Rudd said after the agreement was announced at the latest Ausmin meeting in San Francisco.
The annual meeting is held between the US State and Defence Secretaries and the Australian Foreign and Defence Ministers, and replaced the earlier three-nation talks that included New Zealand until the Anzus split of the 1980s.
The measures will have deep implications for Australia, which regards US power as the guarantor of its security, and which already has close ties ranging from training and exchanges to spy bases and operations in Afghanistan.
As well as greater US military access to mainland Australia, cyber security and co-operation in space - including a military satellite partnership - the two countries will further boost the ability of their forces to work together.
Australia already operates a wide range of American equipment, including Globemaster and Hercules transport aircraft, F/A-18 Hornet fighters, Abrams main battle tanks and other weapons systems.
Australia also plans to re-equip its air force with American joint strike fighters and is building three air warfare destroyers fitted with the Aegis combat system.
"Our discussions have acknowledged that our respective military forces must be postured to respond in a timely and effective way to the range of contingencies that may arise in our region, including humanitarian assistance and disaster relief, and to enhance our ability to work with the armed forces of regional partners," the communique said.
The two countries have agreed to a common approach to the region's emerging power structure, although careful to avoid disturbing China.
The communique said Australia would work more closely with Japan, increasing training and the ability of the three militaries to work together, and improve policy co-ordination.
Australia and the US would also work closely with South Korea on defence and security issues, including efforts to deter further provocations by North Korea.
The communique welcomed the emergence of a "stable, peaceful and prosperous China" and said the US and Australia would encourage a positive and comprehensive relationship with Beijing, including beneficial economic ties and "healthy, reliable and continuous" military-to-military relations.
Other policies included deeper strategic ties with India, and stronger defence and security co-operation with Indonesia.
In the Pacific, they intend to work closely to strengthen democracy, support economic reform, enhance good governance, encourage environmental sustainability and address the impacts of climate change.
They said they would support the protection of the region's fisheries, enhance maritime monitoring, and work to deliver equitable and sustainable outcomes in the Pacific.